The present invention relates to a new and distinct variety of Yucca, commonly known as soapwort, which is grown for use as an ornamental plant for planted containers or for planting in the landscape. ‘Silver Anniversary’ is known botanically as Yucca filamentosa x Yucca pallida and will be referred to hereinafter by the cultivar name ‘Silver Anniversary’.
‘Silver Anniversary’ arose from a Yucca breeding program commenced by the inventor in a nursery in Raleigh, N.C. in 2013. The goals of the breeding program were to develop novel varieties which grow and multiply rapidly while maintaining a compact habit, and developing varieties with striking foliage color and cold-hardiness in zone 7b. ‘Silver Anniversary’ was selected from a population of diverse seedlings which were raised from seed arising from the open-pollination of two species of Yucca: the female parent, an unknown Yucca filamentosa, commonly known as Adam's needle, and the male parent, an unknown Yucca pallida, commonly known as pale Yucca. A single seedling, designated ‘Silver Anniversary’, exhibited a combination of greatly increased vigor, presumably arising from the more vigorous species Yucca filamentosa, with the attractive powder-blue colored foliage of Yucca pallida. 
‘Silver Anniversary’ was first propagated in 2016 at a nursery in Raleigh, N.C., using the method of division of underground stems. The inventor has observed that all asexually reproduced plants of ‘Silver Anniversary’ have remained stable and have reproduced true to type in successive generations of asexual reproduction via division of underground stems.